Transportation Fuels from Algae: Addressing Bangkok’s Petroleum Needs

The purpose of this study is to assess the practicality of algal biofuel production and consumption in Bangkok, Thailand based on the environmental impacts of and ability to offset the petroleum equivalents. A life cycle assessment was conducted to determine the environmental impacts of algal biofuels - biodiesel, ethanol, and compressed biomethane - replacing low-sulfur diesel, standard gasoline, and compressed natural gas (CNG), respectively. Three scenarios with two algae strains were compared for the production of biofuels using net energy ratio (NER) and vehicle kilometers traveled (VKT). For B. braunii, the biodiesel and compressed biomethane producing scenario had the highest VKT of 1,220,000 and an NER of 1.26 using a functional unit of 1 hectare of algal ponds. For the “generic” strain, biodiesel and compressed biomethane produced the highest VKT of 1,200,000 with a NER of 1.25. For B. braunii and generic strains, the production of only compressed biomethane showed NERs of 1.45 and 1.50 respectively, but VKTs of 936,000 and 976,000. Environmental impacts from algal biofuels are higher than petroleum fuels in all categories considered. Available land area would yield enough algal biofuels to replace <1% of petroleum fuel usage. While there is a positive energy ratio associated with the production of algal fuels, Bangkok’s planners need to consider the limited land availability and the higher pollution from algal fuels before committing to an algal biofuel program. Keywords: Algae, biofuels, B. braunii, life cycle assessment, petroleum, renewable.